Production of laminated plane building components comprisng a thermoplastic inner layer and metal outer plies

ABSTRACT

A process for the production of plane building components, comprising relatively thick inner ply of a thermoplastic and relatively thin outer plies of metal. In the process a board is prepared continuously from a polyethylene by means of an extruder at elevated temperature, the board thus obtained is continuously covered on each side first with a film of an ethylene polymer containing carboxyl groups by means of at least one pair of rollers and then with metal sheeting, the whole being made into a sandwich assembly under roller pressure and the plane building component formed being cooled to ambient temperature.

United States Patent Inventors Appl. No, Filed Patented AssigneePriority PRODUCTION OF LAMINATED PLANE BUILDING COMPONENTS COMPRISNG ATHERMOPLASTIC INNER LAYER AND METAL OUTER PLIES 5 Claims, 1 Drawing Fig.

U.S. Cl 156/244,

156/309 Int. Cl B290 9/00 Field of Search 156/244,

Primary Examiner-Carl D. Quarforth Assistant Examiner-Stephen J.Lechert, Jr.

Attorney-Johnston, Root, OKeefe, Keil, Thompson &

Shurtleff ABSTRACT: A process for the production of plane buildingcomponents, comprising relatively thick inner ply of a thermoplastic andrelatively thin outer plies of metal. In the process a board is preparedcontinuously from a polyethylene by means of an extruder at elevatedtemperature, the board thus obtained is continuously covered on eachside first with a film of an ethylene polymer containing carboxyl groupsby means of at least one pair of rollers and then with metal sheeting,the whole being made into a sandwich assembly under roller pressure andthe plane building component formed being cooled to ambient temperature.

PAIENTEDum 26 Is 3,616,019

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Z MUELLE MM E AHLIN HANS E RF ALFRED H ATT'YS PRODUCTION OF LAMINATEDPLANE BUILDING COMPONENTS COMPRISNG A THERMOPLASTIC INNER LAYER ANDMETAL OUTER PLIES The present invention relates to a process for theproduction of plane building components which are composed of arelatively thick inner ply of a thermoplastic and relatively thin outerplies of metal.

In conventional methods of this type, the building components areprepared for example using extrusion coating equipment. A board ofpolyethylene (which is to be the relatively thick inner ply) first hasapplied to it an adhesion promotor between the polyethylene and theouter plies of metal. This adhesion promoter is either a contactadhesive or a two-component adhesive based on an epoxide.

The said methods have the disadvantage that they are complicated and theadhesion between metal and plastics material (polyethylene) leaves muchto be desired. When contact adhesives are used only low-creep rupturestrength and inadequate resistance to high temperatures are achieved. Onthe other hand, bonding by means of two-component adhesives requiresexpensive apparatus and long curing times and gives relatively brittlejoints; the components are moreover incapable of being deep-drawn.Furthermore, in order to obtain a relatively good bond it is alwaysnecessary to subject the metal and polyethylene surfaces to be bonded toa pretreatment, for example an oxidizing pretreatment.

The present invention has for its object to provide a method of the typementioned above which does not have the said disadvantages or has themin considerably smaller degree.

We have now found that this object is achieved when the outer plies ofmetal are applied to the polyethylene (which is to be the relativelythick inner ply) by means of a special adhesion-promoting layer underspecial process conditions.

The present invention accordingly consists in a process of the typementioned above in which a board having a thickness of from 1 to 20 mm.is prepared continuously from a polyethylene having a density of 0.916to 0.965 g./cm. by means of an extruder at a temperature of the materialof 100 to 250 C. (preferably 150 to 220 C.), the board thus obtained isthen covered continuously on each side by means of at least one pair ofrollers at a temperature of the material of 100 to 250 C. (preferably110 to 180 C.) first with a film having a thickness of 0.01 to 0.5 mm.of an ethylene polymer which contains carboxyl groups, is devoid ofpolymerized units of esters of ethylenically unsaturated carboxylicacids and has a melting range of from 70 to 130 C., a Shore hardness Cof 50 to 95 and a modulus of elasticity of 50 to 2,500 kg./cm. and thenwith a sheet of metal which is thinner than the polyethylene board by afactor of from 3 to 30 (preferably from 5 to the whole being combined toa sandwich element under a roller pressure of 0.1 to 4 kg./cm. and theplane building component thus obtained being cooled or allowed to coolto ambient temperature.

Commercial polyethylene having a density of 0.916 to 0.965 gJcm. issuitable for carrying out the process according to the invention. Theadhesive film to be used according to the invention consists of anethylene polymer known per se which can be processed into film bymethods conventionally used for ethylene polymers. Conventional metalsheeting may be used; for example sheeting of aluminum, copper, brassand steel have proved to be suitable.

The production of the plane building components may be carried out bymeans of conventional equipment for the production of plastics boards ata production rate of up to 2.5 meters per minute. This equipmentconsists in the present case of an extruder, at least one pair ofrollers and a cooling zone. The bond between polyethylene, adhesive filmand sheet metal is effected by bringing these components into contact inthe nip of at least two rollers, the polyethylene which is still hotcausing the adhesive film to melt temporarily. After bonding has takenplace, the building component is cooled or allowed to cool to ambienttemperature.

The accompanying drawing shows diagrammatically a hopper 1 containinggranulated polyethylene. an extruder 2,

the polyethylene board 3 formed, adhesive films 4, sheet metal 5,rollers 6 and building component 7.

Building components prepared according to the invention may be shaped byconventional methods, for example bent, rounded, turned over, flanged,embossed, corrugated or deepdrawn. They may be joined with each other orwith other materials by riveting, heat sealing, bonding, nailing,screwing or clamping.

The building components may be used in many ways, a few of them beinggiven below:

The building components may be used in buildings as selfsupportingroofs, facade boards, partitions, ventilation shafts, balcony railings,comices and garage doors. Walls of silos or walls and linings of stablesmay also be made advantageously with them.

In road construction the building components are suitable for examplefor road signs, antidazzle screens or safety barriers. In vehicleconstruction the building components may be used with advantage for thewalls and roofs or railway cars, for sun roofs and insulating jacketsfor tank cars because of their favorable ratio of rigidity to weight,good resistance to corrosion and good thermal insulation. In roadvehicles they are suitable for example for box bodies, sidewalls anddriver's cabins of lorries or for outer walls of caravans. lnshipbuilding they are suitable for the construction of inner walls andsuperstructures.

The building components may also be used in the construction of vesselsand containers, for example for food troughs, water reservoirs, casingsfor instruments or covering hoods for machines and equipment.

The invention is illustrated by the following Example.

EXAMPLE A board having a thickness of 3 mm. is extruded continuously inan extruder having a mm. screw and a sheeting die 600 mm. in width at atemperature of the material of 190 C. from a polyethylene having adensity of 0.918 g./cm.. The board which is still hot (temperature about160 C.) is coated on each side with a 0.1 mm. thick film of an ethylenepolymer containing carboxyl groups, devoid of polymerized units ofethylenically unsaturated carboxylic acids and having a melting range offrom 98 to 104 C., a Shore hardness C of77 and an elasticity modulus of1,850 kg./cm. and at the same time, also on each side, with an aluminumfoil having a thickness of 0.3 mm., the whole then being brought intointimate contact by passage through a pair of rollers heated to 70 C.under a roller pressure of l kg./cm. The whole is then allowed to cool.

We claim:

1. A process for the production of building components comprising arelatively thick inner ply of a thermoplastic polymer and relativelythin outer plies of metal, which process comprises extruding a sheethaving a thickness of l to 20 mm. of a polyethylene having a density of0.916 to 0.965 g./cm. at a temperature of the polyethylene of to 250 C.,applying to the resultant sheet on each face at a temperature of thepolyethylene of from 100 to 250 C. (a) first a film having a thicknessof 0.01 to 0.5 mm. of an ethylene polymer containing carboxyl groups,devoid of units of polymerized esters of ethylenically unsaturatedcarboxylic acids and having a melting range from 70 to C., a Shorehardness C of from 50 to 95 and a modulus of elasticity of 50 to 2,500kg./cm. and (b) then a metal sheet which is thinner than thepolyethylene sheet by a factor of from 3 to 20, and pressing the sheetsinto a sandwich assembly under a roller pressure of from 0.1 to 4kg./cm."'.

2. A process as claimed in claim I wherein the temperature of saidpolyethylene during extrusion is to 220 C.

3. A process as claimed in claim I wherein the temperature of saidpolyethylene during the applying of said film is from ll0to 180C.

4. A process as claimed in claim I wherein the sheet of 5. A process asclaimed in claim 1 wherein the metal sheet- 'metal is thinner by afactor of from 5 to than the mg issheeting of aluminummoppe brassSteelpolyethylene board.

2. A process as claimed in claim 1 wherein the temperature of saidpolyethylene during extrusion is 150* to 220* C.
 3. A process as claimedin claim 1 wherein the temperature of said polyethylene during theapplying of said film is from 110* to 180* C.
 4. A process as claimed inclaim 1 wherein the sheet of metal is thinner by a factor of from 5 to15 than the polyethylene board.
 5. A process as claimed in claim 1wherein the metal sheeting is sheeting of aluminum, copper, brass orsteel.